This application claims priority from U.S. Provisional Application Ser. No. 61/645,250 filed May 10, 2012.
The present invention relates to an arrangement for opening and closing coverings for architectural openings such as pleated shades and cellular shades.
Usually, a transport system for a covering that extends and retracts in the vertical direction has a fixed head rail which both supports the covering and hides the mechanisms used to raise and lower or extend and retract the covering. Such a transport system is described in U.S. Pat. No. 6,536,503, Modular Transport System for Coverings for Architectural Openings, which is hereby incorporated herein by reference. In the typical covering product that retracts at the top and then extends by moving downwardly from the top (top/down), the extension and retraction of the covering is done by lift cords suspended from the head rail and attached to the bottom rail (also referred to as the moving rail or bottom slat).
Some window covering products are built to operate in the reverse (bottom-up), where the moving rail, instead of being at the bottom of the window covering bundle, is at the top of the window covering bundle, between the bundle and the head rail, such that the bundle is normally accumulated at the bottom of the window when the covering is retracted and the moving rail is at the top of the window covering, next to the head rail, when the covering is extended. There are also composite products which are able to do both, to go top-down and/or bottom-up. Sometimes there is a problem with the movable rail(s) becoming skewed.